A liquid jet recording device (in inkjet printer) for carrying out a variety of types of printing is provided with a conveyer for conveying a recording medium, a liquid jet head (an inkjet head), and a scanner for making the liquid jet head run in a direction perpendicular to the conveying direction of the recording medium. The liquid jet head supplies the liquid jet head with ink (a liquid) from a liquid container (an ink tank) via a liquid supply pipe (an ink supply pipe), and ejects the ink from a jet orifice (a nozzle hole) of a head chip provided to the liquid jet head toward the recording medium. Thus, characters and images are recorded on the recording medium.
The head chip is provided with a jet orifice plate (a nozzle plate) with the jet orifice formed, and an actuator plate, which is bonded to the jet orifice plate, and has a plurality of channels communicated with the jet orifice. Each of the channels of the actuator plate is filled with the ink. In many cases, the jet orifice plate is formed of resin in order to process the jet orifice with high accuracy. In contrast, the actuator plate is formed of a piezoelectric material such as PZT (lead zirconate titanate). In such a configuration, when applying a voltage to the actuator plate, the capacity of the channel varies due to a piezoelectric shear effect. The ink is ejected through the jet orifice using this variation.
The liquid jet head configured in such a manner as described above is attached to the scanner via a base plate including a fixation plate and a head cover (see, e.g., JP-A-2009-34862). In attaching the liquid jet head to the base plate, the liquid jet head is attached so that the jet orifice plate bonded to the head chip and the base plate are bonded to each other.
Incidentally, the head chip needs to be aligned to the base plate for alignment to the scanner. Therefore, there is developed a technology of providing a rib, which projects from a place (a jet orifice guard) opposed to the jet orifice plate in the base plate toward the jet orifice plate, and has contact with the jet orifice plate. The head chip is fixed to the base plate via an adhesive disposed between the head chip and another part of the base plate than the rib while having contact with the rib of the base plate.
Here, if the material of the jet orifice plate and the material of the actuator plate are different from each other, the expansion deformation amount and the contraction deformation amount due to the variation in heat are also different therebetween. Due to the difference in deformation amount, a warpage occurs in the actuator plate. If the warpage occurs in the actuator plate, stress is applied to the adhesive located between the head chip and the base plate. However, since the base plate is provided with the rib having contact with the jet orifice plate, the adhesive sandwiched between the head chip and the base plate is limited in expansion/contraction deformation by the rib, and it becomes difficult to release the stress. As a result, the warpage of the actuator plate is restricted, and the actuator plate also fails to release the stress, and the stress in the actuator plate increases.
Moreover, the actuator plate is provided with the plurality of channels, and is therefore made weak (easy to be broken) against deformation. In particular, the part of the actuator plate exposed from the jet orifice plate, namely the part to which the jet orifice is not bonded, is not provided with the reinforcement by the bond with the jet orifice plate, and is therefore made particularly weak against deformation. Therefore, in the case in which the stress due to the heat variation of the actuator plate cannot be released to increase the stress, there is a possibility that the actuator plate is damaged.
Therefore, the invention is to provide a liquid jet head and a liquid jet recording device capable of preventing the damage of the actuator plate without degrading the quality of characters and images to be recorded on the recording medium.